Fix assertion failure with .MTS files.

These files have subs which start but are never officially
finished; this means there are no `to' times to find in
find_subtitle_to.  Cope with this by stopping the previous sub when
a new one arrives if there hasn't been a proper "stop" in the
mean time.

1 files changed, 2 insertions, 1 deletions

diff --git a/src/lib/ffmpeg_examiner.h b/src/lib/ffmpeg_examiner.h
index 6fd3220d4..27bff08b4 100644
--- a/src/lib/ffmpeg_examiner.h
+++ b/src/lib/ffmpeg_examiner.h
@@ -85,5 +85,6 @@ private:
 	Frame _video_length;
 	bool _need_video_length;
 
-	boost::optional<ContentTime> _last_subtitle_start;
+	typedef std::map<boost::shared_ptr<FFmpegSubtitleStream>, boost::optional<ContentTime> > LastSubtitleMap;
+	LastSubtitleMap _last_subtitle_start;
 };